Andrew Moreton
Adventurer
A sidetrack this week was interest in tracking down the Ziggurat of Avilona which would need flying. This lead to Hot Air balloons and Kites would they work in this world? I have not come to a conclusion yet
Hot air balloons are a different topic. (And I just went on my first RL hot air balloon ride this weekend, which is why I clicked on your thread!) Remember that hot air balloons have no way of steering: the only "controls" you have on a hot air balloon is that they can use a burner to rise slowly, they can drop a sandbag to rise quickly, and if they leave the burner off, they descend slowly. And you can open a flap on the side to let out air in order to rotate, but not to propel.
Hot air balloon rely on wind in order to get from place to place. There is a nominal amount of control a hot air balloon operator has due to the fact that different air currents go at different speeds and different directions at different altitudes, so by rising or falling into the right jet stream, they can kindof influence the direction that they're going. (In order to figure out whether they should rise or descend, balloonists will drop a small air-inflated balloon, and watch which way it falls, or look at birds above them, and make a guess as to what's going on up there.) Also note that prevailing wind directions often change at sunrise and sunset, which naturally sets up certain balloon "routes."
If a thing wouldn't fly in the real world, it won't fly in (pre-adventure 10) ZEITGEIST (with the exception of brief flight magic [and the even tighter exception of Gale]).